Audio and Video

H.264 license issues

Google called the MPEG-LA’s bluff, and won article has one interesting point on H.264 to think about: those H.264 licenses embedded in Windows, OS X, iOS, your ‘professional’ camera, and so on, do not cover commercial use. This means according to article that if you shoot a video with your camera in H.264, upload it

HDMI and ground loops

In my Audio and video signal susceptibility classes I wrote that digital video interfaces like DVI and HDMI can also have ground loop noise problems as they use a combination of balanced and unbalanced signals. Ground loop problem is one very possible source of intermittent problems over long distance in HDMI installations. This article is

HDMI HDCP hacking

HDMI uses copy protection system called HDCP. And I have know for some years that HDMI copy protection broken. But based on recent information that has popped out it seems that it is even more broken that I thought that it was. Hackaday tells that HDMI breakout lets you sniff HDCP crypto keys and points

Balanced Line Technology

Balanced inputs and outputs have been used for many years in professional audio, but profound misconceptions about their operation and effectiveness still survive. Conventional wisdom about them is sometimes wrong. Balanced Line Technology web page gives you a good look at the balanced line technology in audio applications. The balanced line technology is also applicable

Audio and video signal susceptibility classes

My article Signal reference grids in the data center shows that different types of data communication interfaces are classified into susceptibility classes: Data communication interface classification Susceptibility class: Low immunity Interfaces in class: Parallel ports, RS-232 ports, Proprietary back-plane, Video cables Characteristics: Copper cabling with ground referenced signals. Any shift in ground voltage between the

Grounding and EMI

One of the most common direct coupled noise sources is when the ground which is being used for reference or return is not referenced to earth as expected. This is especially prevalent in sensitive high-gain circuits. Grounding and Shielding Existing Equipment – How to effectively minimize EMI issues when best practices are not available is

Measuring pictures with software

Reverse engineering salvaged part footprints article mentioned an interesting idea to use a microscope software to process an image of the board. Measuring with Software article mentions an interesting free computer-based microscopy software MiCam. MiCam software allows (once you have calibrated it) you to draw more lines on the photos and calculate and display the

Audio and video 2013

Cell phones with build in cameras are replacing cheap pocket size digital cameras and video cameras. Best cell phone cameras can be better in many ways than cheap pocket digital cameras from few years back. And most people do not want to carry separate devices for each function (at least without a very good reason),